Macromolecule ions metal-containing

In a concurrently published report [160] Crooks and coworkers reported similar MUA-SAMs modified by covalent linking of hyperbranched macromolecules. These films containing a high density of surface carboxylic acid groups could selectively bind metal ions or undergo chemical modification. 

Template Polymers. Template effects in chelating polymers constitute an interesting development in the field of metal containing polymers. The Template effects are interpreted by the fact that the small molecule is templating a pattern in the macromolecule which can be recognized by the same molecule in a subsequent process. The idea is to prepare a polymer from the metal-chelated monomer, to remove the metal ion, and then to measure the selectivity of the prepared polymer for the metal ion of the template [36]. Typical examples of template systems are 4-vinyl-4 -methylbipyridine (Neckers [36]) and 1-vinyl-imidazole (Tsuchida [37]). These are polymerized in presence of divinylbenzene [36] and appropriate metal salts (Co2+, Cu2+, Ni2+, Zn2+). The template metal ions are removed by acid leaching and the polymer subsequently used for metal ion absorption studies (Fig. 16). 

The time necessary to remove one monolayer during a SIMS experiment depends not only on the sputter yield, but also on the type of sample under study. We will make an estimate for two extremes. First, the surface of a metal contains about 1015 atoms per cm2. If we use an ion beam with a current density of 1 nA cm-2, we then need some 150000 seconds (about 40 hours) to remove one monolayer if the sputter yield is 1, and 4 hours if the sputter rate is 10. However, if we are working with adsorbed macromolecules and polymers, we need significantly lower ion doses to remove a monolayer. It is believed [4] that one impact of a primary ion affects an area of about 10 nm2, which is equivalent to a circle of about 3.5 nm diameter. Hence, if the sample consists for example of a monolayer film of polymer material, a dose of 1013 ions cm-2 could, in principle, be sufficient to remove or alter all material on the surface. With a current density of 1 nA this takes about 1500 seconds or 25 minutes only. For adsorbates such as CO adsorbed onto a metal surface, we estimate that the monolayer lifetime is at least a factor of 10 higher than that for polymer samples. Thus, for static SIMS, one needs primary ion current densities on the order of 1 nA cm 2 or less, and one should be able to collect all spectra of one sample within a few minutes. 

Macromolecular complexes (MMCs) that contain at a macromolecule, a metal ion or metal complex interacting ionic by bonds (electrostatically), donor-acceptor bonds (coordinative bonds), or covalent bonds (Fig. 4). In these, the metal MMC is a specific pendant substitute. 

I. Studies of halide ion binding to native metal-containing or metal-free proteins or other macromolecules. 

In metal-containing macromolecules or macromolecular metal complexes (MMC) (article in the previous edition of the Handbook see [1]) suitable compounds are combined to materials with new unusual properties organic or inorganic macromolecules with metal ions, complexes, chelates or also metal clusters. These combinations result in new materials with high activities and specific selectivities in dilferent functions. This article concentrates on synthetic aspects of artificial metal-containing macromolecules. Properties are shortly mentioned, and one has to look for more details in the cited literatures. In order to understand what kind of properties are realized in metal-containing macromolecules, in a first view functions of comparable natural systems (a short overview is given below) has to be considered ... 

Type I A metal ion, a metal complex or metal chelate is connected with a linear or crosslinked macromolecule by covalent, coordinative, chelate, ionic or Ti-type bonds (Figure 1). This type I is realized by binding of the metal part at a linear, crosslinked polymer or at the outer or interior surface of an inorganic support. Another possibility uses the polymerization or copolymerization of metal containing monomers. 

Because in most cases no clear lUPAC nomenclature exists for metal-containing macromolecules or macromolecular metal complexes, it is not possible to obtain by a Chemical Abstract literature search a detailed information on them. One has to look for each individual metal, metal ion, metal complex, metal chelate, ligand or also polymer. For type I usually rational nomenclature is used (for example cobalt(II) complex with/ of poly(4-vinylpyridine) or 2,9,16,23-tetrakis(4-hydroxyphenyl)phthalocyanine zinc(II)... 

Okamoto, Y., Ueba, Y., Dzhnibekov, N. F., Banks, E. Rare earth metal containing polymers. 3. Characterization of ion-containing polymer structures using rare earth metal fluorescence probes. Macromolecules, 14,17-22 (1981). 

The behaviour of natural ligands has been discussed in Section 4.3.3. In addition to the direct effect of complexation that is related to a decrease in the free ion activity, it has been shown that some ligands, in particular the HS, can be sorbed directly to biological surfaces, in the presence or absence of the trace metal [228,229]. This result is likely due to the fact that HS and similar macromolecules contain hydrophobic moieties that facilitate their adsorption to the plasma membrane and cell wall [157,230,231]. Because adsorption is expected to occur primarily with sites that are independent of the transporters,... 

Liu B, Yu W-L, Pei J, Liu S-Y, Lai Y-H, Huang W (2001) Design and synthesis of bipyridyl-containing conjugated polymers effects of polymer rigidity on metal ion sensing. Macromolecules 34 7932-7940... 

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